کاهش آلودگی در هلند: ارزیابی تعادل عمومی کاربردی پویا

This paper introduces a dynamic applied general equilibrium model with bottom-up abatement information for important environmental themes, which can be applied to a wide variety of countries. Empirical abatement cost curves determine the characteristics of abatement and substitution possibilities between pollution and abatement. The analysis of efficient reduction strategies for the Netherlands shows that the costs of current environmental policy targets can be limited via a mixture of technical abatement measures, economic restructuring and a temporary economic slowdown. Smog formation is the most costly environmental theme, due to the absence of sufficient technical abatement options.

The economic costs of environmental policies can be substantially reduced if an assessment is made of the most efficient policies and technological options. The costs of measures are determined by the direct costs of emission reductions (marginal abatement costs) and the indirect effects induced by these policies, such as sectoral shifts in production and consumption. These indirect effects can be properly captured by using a multi-sectoral applied general equilibrium model. The vast majority of dynamic AGE models for environmental policy issues focus purely on Climate change (for an overview, see Conrad, 1999 and Harrison, Hougaard Jensen, Haagen Pedersen, & Rutherford, 2000). These energy–environment–economy models assume that end-of-pipe measures are not available or prohibitively costly compared to fuel switches, and therefore can be neglected in the model. Recent contributions to the field include Bye (2000), Wendner (2001), Dissou, MacLeod, and Souissi (2002), Gerlagh and van der Zwaan (2003) and Böhringer and Welsch (2004). Models that capture several environmental problems simultaneously are rare; a notable exception is Xie and Saltzman (2000), who distinguish between pollution abatement activities for air quality, water quality and soil quality. At the other end of the spectrum are bottom-up models that contain detailed empirical information on the technical characteristics of specific abatement options, e.g. RAINS (Alcamo, Shaw, & Hordijk 1990). Nowadays, most of these models include estimates of the associated direct costs of the measure; they are, however, not capable of assessing the indirect economic effects. The easiest way to integrate the bottom-up model with a top-down economic model is via so-called soft-linking. In this approach, two separate models are specified, and the outcomes of one model are entered as exogenous input into the other model. The converging outcome is then achieved via an iterative procedure. An example of this approach is given in Jacobsen (1998). Other studies aim at integrating both the bottom-up and top-down modules into one model (so-called hard-linking). Noteworthy examples of such integrated models are the model by Böhringer (1998) and the NEMO energy model (Koopmans & te Velde, 2001). Full-scale estimation of abatement costs is not common in top-down environmental-economic models. The detailed description of abatement processes in terms of economic inputs as used in Nestor and Pasurka (1995a) is an exception; Nestor and Pasurka (1995b) show that a proper specification of abatement costs is vital for quantitative estimates of the economic costs of environmental policy. The aim of this paper is to assess the long-run economic costs of environmental policies in the Netherlands, using a dynamic AGE model augmented with several environmental themes and special attention to the (empirical) characteristics of pollution abatement. The detailed information on abatement costs, in combination with a consistent assessment of the indirect effects, provides a suitable framework for an empirical evaluation of environmental policies in the Netherlands. The novel contribution of this paper is that a consistent methodology that covers both direct and indirect effects is used, allowing for a proper assessment of the interactions between sectoral economic activity and multi-pollutant environmental policy. Thus, the model facilitates to make both ex ante and ex post assessments of a wide variety of environmental policy options, for each of the environmental themes, including the various interactions amongst the policy options. It can be applied for individual countries, whereas in this paper we report on environmental policy making in the Netherlands. The set-up of this paper is as follows: Section 2 provides an overview of the model; Section 3 deals with the data for the Netherlands. The results of the model simulations for Dutch environmental policies are discussed in Section 4; Section 5 concludes.

This paper contributes to the understanding of the dynamic feedback mechanisms between environmental activity and abatement in the context of an ex ante assessment of multi-pollutant environmental policies. The consistent integration of essential bottom-up information on abatement measures in a top-down framework has been shown to be both implementable and applicable. In this way, a better assessment can be made of both the direct and indirect economic effects of actual and proposed environmental policies for several major environmental themes. The empirical application to the Netherlands firstly shows that if environmental policies can be implemented simultaneously and in a cost-effective manner, the economic costs of current Dutch environmental policy targets can be limited to about 11% of GDP via a mixture of adoption of technical abatement measures, economic restructuring and a temporary slowdown of economic growth. It will be possible for the Netherlands to decouple environmental pressure and economic growth, given the availability of technical abatement measures and substitution possibilities within the economy. Secondly, more stringent environmental policies imply more emphasis on economic restructuring as a means to achieve the targets. If policy makers impose restrictions on these changes in sectoral structure, they have to realise that the macro-economic costs of the policy will increase substantially and/or that the policy target may not be reached. Moreover, the focus of policy makers on the economic threats of environmental policy is not justified, as a strict environmental policy can create new opportunities for relatively clean (services) sectors and especially for producers of abatement technologies. Thirdly, there are advantages as well as disadvantages to internationally co-ordinated environmental policy. Polluters and their interest groups mostly stress the severe loss in competitive position of domestic producers in case of unilateral environmental policy. A multilateral policy, however, prevents a specialisation of the domestic economy in environmentally friendly production processes. Fourthly, according to the simulations with the DEAN model, Smog formation will become the dominant environmental theme in the coming decades, mainly due to a lack of technical abatement options to reduce VOC emissions. It is therefore of utmost importance that the government does not hamper research and development on technologies that can reduce VOC emissions. If new technological options for the theme Smog formation are not invented, the costs of environmental policy may be so high, and specific sectors may be so severely affected, that policy makers will have to adjust the policy target under pressure from threatened groups of polluters. Fifthly, postponing GHG emission reductions and co-ordinating these reductions with other environmental policies can significantly reduce the costs of Climate change policy, while environmental quality is hardly affected. Policy makers should not immediately panic when GHG emission reductions are smaller than the intermediate targets. The cost-effective path of GHG emission reductions incorporates low emission reductions in the first few decades. This does not imply inaction on behalf of the government. There are important time lags, especially in the build-up of capital, and slow adaptation to a less carbon-intensive economy can lower costs. Finally, the simultaneous analysis of environmental policy for several environmental themes leads to substantially lower economic costs because of the many interactions between the different themes. These interactions are both environmental and economic and the cost-effective outcome is to coordinate the timing of the different environmental policies. These interactions should be kept in mind when interpreting the numerical outcomes of sector- or theme-specific studies. Several caveats remain with respect to methodology and data, especially regarding the economic benefits of environmental policy. These hopefully provide a stimulus for further research in this field, as an improved comprehension of the interactions between economic growth, sectoral structure, pollution and abatement can lead to better environmental policies. It is evident that such improved understanding is essential; there are significant direct and indirect economic costs of environmental policies, which undoubtedly await in the coming decades, as illustrated in this paper.